This invention relates to current sensing devices, and more specifically relates to a Hall sensor mounted in the airgap of the magnetic core of an inductor which has some other function in an electrical circuit.
Many electrical circuits require one or more inductor devices and also require one or more current sensors which monitor the current in the inductors. Such inductors are commonly inductors consisting of a magnetic core having a winding thereon. Such current sensors commonly consist of a magnetic core having an airgap in which a Hall-effect element is placed. These sensors must be able to deliver an isolated signal that represents the a-c line input current, including any d-c component. The current to be sensed is carried by a winding on the core, which winding may be either a single turn or a multiple turn winding.
Such prior art structures therefore, require two magnetic cores, one for the inductor and another for the Hall-effect current monitor. These two cores and their windings have an accordingly increased mass and volume of the circuit in which they are disposed.
In accordance with the invention, the magnetic cores of the circuit inductor and of the Hall sensor are combined, and the Hall-sensor crystal is inserted into the airgap in the inductor core. Consequently, the mass and volume of the combined circuit inductor and Hall sensor is substantially reduced.